Between 1897 and 1899, while carrying out excavations in the prison of Chillon Castle, archaeologist Albert Naef discovered and opened loopholes that had been walled in during the 14th century. On the brush of the seventh, he discovers "consecration crosses". These motifs were painted, engraved or sculpted on the walls, columns or pillars of churches at the time of their "dedication", a ceremony to make them holy and vowed to God.
Naef finds in Chillon's accounts that one of the loopholes was sealed in 1388 and dates the crosses to the 14th century as well. Without reaching a decision, he associates their presence with two events that occurred in the castle during this period. The first one is the massacre of the Jews of Villeneuve in 1348, right in the middle of a plague epidemic, accused of poisoning the fountains. In Chillon, the populace seized about forty Jews who were imprisoned there and beat them. They were then taken to the village square and, without any trial, men, women and children were burned on several pyres built on the lakefront. The second one is the hunt for a basilisk, a monster feared for his poisoned breath and petrifying abilities, in 1379. Sources mention that it was sought in the "crota", i.e. a hole or basement in old local dialect, without further precision. The exact location of the crota is not unanimously accepted by archaeologists. Naef also places it inside one of the fortress' defence towers on the other side of the site. In both cases, the presence of consecration crosses would symbolize the purification of the prison.